Abstract

This study was conducted to examine the phenomenon of task partitioning among associations of foundresses of the primitively eusocial wasp Belonogaster juncea juncea (F.). The time-activity budget for five main behavioral categories (foraging, building, feeding, inactivity, and reproduction) for each foundress belonging to trigynic associations was recorded using the instantaneous scanning technique. After ranking the individuals on the basis of agonistic encounters, data were submitted to a canonical discriminant analysis. The results show behavioral differences between individuals of each rank. The proportion of time allocated to foraging behavior is a good rank index. The females of the first rank spent less time on foraging behavior and significantly more time (13.6% of their time) on reproductive behavior than females of other ranks. The females of the second rank also spent less time on foraging behavior and showed a tendency toward building behavior. The females of the third rank spent significantly more time (77.28% of their time) on foraging behavior. The behavioral profile of each foundress was therefore determined by its rank on the dominance scale.